This classic by Gillette and Hill introduces readers to modern-day (back in the 1800s – haha!) concrete construction. Check out this excerpt:

The derrick buckets by which the concrete was hoisted and handled to the work were of special construction. A bucket was desired which would serve several distinct purposes. It must first be able to hold a full mixer batch of material, since, with the derrick arrangement, economy in hoisting necessitated hoisting in large units and also because storage capacity was required of the bucket for wheelbarrow work. The four derricks did not command the entire area of a floor; there were corners and other irregular areas outside of the circles covered by the several booms over which the concrete must be distributed[Pg 486] by barrows or carts. A bucket large enough to supply the barrows, while a second bucket was being lowered, charged from the mixer and hoisted, was required. In the second place, a bucket was required whose contents could be discharged all at once or in smaller portion at will. Finally a bucket was desired which could be made to distribute its load along a narrow girder form or in a thin sheet for a floor slab.

To meet these requirements the bucket shown in Fig. 222 was designed. It held 42 cu. ft., or about 1.55 cu. yds. of concrete. It had a hopper bottom terminating in a short rectangular discharge spout closed by a lever operated under cut gate, which could be opened as much or as little as desired. To the underside of the bucket there was attached a four-leg frame in which the bucket stood when not suspended. Ordinarily, that is within the circles commanded by the derricks, the buckets were discharged suspended and directly into the forms, the character of the discharge gate permitting a thin sheet to be spread for floor slabs or a narrow girder or wall form to be filled without spilling or shock. For wheelbarrow work outside the reach of the derricks the mode of procedure was as follows: A timber platform about 3 ft. high and having room for standing two buckets was set just on the edge of the circle commanded by the derrick boom. Two buckets were used. A full bucket was hoisted and set on the platform, with its spout overhanging. This bucket served as a storage bin for feeding the wheelbarrows while the second bucket was being lowered, charged and hoisted to take its place on the platform, and serve in turn as a storage hopper.

PLACING AND RAMMING.—A wet concrete is usually used in building work except on occasions, for exterior wall work and except for pitch roof work, where a wet mixture would run down the slope. Placing and tamping are therefore, essentially pouring and puddling operations. The pouring should be done directly from the barrows, carts, or buckets if possible; dumping onto shoveling boards and shoveling makes an extra operation and increases the cost by the wages of the shoveling gang. Where shoveling boards are necessary, take care that they are placed close to the forms being filled, as it is wasteful of time to carry concrete in shovels, even for[Pg 487] a half dozen paces. Before pouring any concrete, the inside of the forms should be wet down thoroughly with a hose or sprinkler, if a hose stream is not available. The final inspection of forms and reinforcement just before concreting will have made certain that they are ready for the concrete, so far as line and level of forms and presence and proper arrangement of the reinforcement are concerned, but the concrete foreman must watch that no displacement occurs in pouring and puddling, and must make certain particularly that the forms are clean.

In pouring columns it is essential that the operation be continuous to the bottom of the beam or girder. It is also advisable to pour columns several hours ahead of the girders. Puddling should be thorough, as its purpose is to work the concrete closely around the reinforcement and into the angles of the mold and to work out air bubbles. A tool resembling a broad chisel is one of the best devices for puddling or slicing. In slab and girder construction, the pouring should be continuous from bottom of girder to top of slab. Work should never be stopped-off at horizontal planes. As in columns, careful puddling is essential in pouring beams. In slab work, the concrete is best compacted by tamping or rolling. A broad faced rammer should be used for tamping wet concrete, or a wooden roller covered with sheet steel, weighing about 250 lbs., and having a 30-in. face.

Theoretically, concreting should be a continuous operation, but practically it cannot be made so. Bonding fresh concrete to concrete that has hardened, though it has been done with great perfection by certain methods as described in Chapter XXIV, must still be held as uncertain. Ordinarily, at least, a plane of weakness exists where the junction is made and in stopping off work it should be done where these planes of weakness will cause the least harm. Experts are by no means agreed on the best location of these planes, but the following is recognized good practice. Work once started, pouring a column, should not be stopped until the column is completed to the bottom of the girder. For beams and girders; stop concrete at center of girder with a vertical face at right angles to the girder, or directly over the center of the columns; in beams connecting with girders, stop concrete at center of[Pg 488] span, or directly over center of connecting girder; stop always with a vertical face and never with a sloping face, and never with a girder partly filled. For slabs; stop concrete at center of span, or directly over middle of supporting girder or beam; stop always with vertical joints. If for any cause work must be stopped at other points, than those stated, the fresh concrete and the hardened concrete must be bonded by one of the methods described in Chapter XXIV.

CONSTRUCTING WALL COLUMNS FOR A BRICK BUILDING.—The columns, 12 in number, were constructed to strengthen the brick walls of a power station and were built as shown by Figs. 223 and 224, one at a time. The staging, 50 ft. high and 4×6 ft. in plan, was erected against the wall which had been shored, a portion of the wall was cut out and forms erected and the concrete column substituted for the section of wall which was removed. The staging was then moved into position for another column.

Wow. How interesting! The amount of technical knowledge present in this 19th Century book!